Internal-combustion engine



March 23 1926.

R. A. YEARSLEY INTERNAL COMBUSTION ENGINE 1924 3 Sheets-Sheet 1.

Filed June March 23,1926. 1,578,228

R. A. YEARSLEY INTERNAL COMBUSTION ENGINE Filed June 2, 1924 3 Sheets-Sheet 2 March 23 1926.

R. A. YEARSLEY INTERNAL CONBUSTION ENGINE 19 s Sheets-Sheet 5 Filed June Patented Mal-.23, 1926.

UNITED STATES r 1,578,228 PATENT OFFICE.

RALPH nennnonxnnnsnnx, or was]: EALING, LONDON, ENGLAND.

I INTERNAL-COMBUSTION ENGINE.

Application filed June 2,

To alt whom it may concern:

Be it known that I, RALPH ALGERNON YEARSLEY, a subject of the King of Great Britain, residing at Vest Ealing, London, England, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

This invention relates to improvements in that type of internal combustion engines in which the shaft tobe driven is located between the power piston and a piston employed to act as a pump.

The present invention relates to an internal combustion engine, in which there is a one-piece structure comprising a coaxial power cylinder and larger diameter pump cylinder, within which is located a one-piece coaxial power and pump piston fitting therein and having its opposite ends closed.

Now according to the present invention, the crank shaft is carried in diametricallyopposite hearings in the side wall of the pump cylinder, the pump piston within the latter cylinder having diametrically opposite slots in its wall extending in the direction of the axis of the power and pump pistons to permit of the passage of the crank shaft and of the reciprocation of the pistons, the crank shaft having a crank located within the pump piston.

The pump piston is constructed with two cross heads at a distance apart, which cross heads extend across the interior of the pump piston transversely of the axis of the crank shaft, the cross heads having opposed'guiding surfaces on their inner faces. A slide block is located between said cross heads, bearing upon the opposed guiding surfaces fixed on the inner faces of the cross heads, and the sliding block has hearings to receive the crank pin of the crank shaft.

The pump piston is conveniently formed with diametrically opposite openings in its wall at the ends of the said crossheads, to.

aforesaid is fitted on.its inner face with a guide, the said guides having their opposed bearing faces segmental and concentmc with 1924. Serial No. 717,323.

each other, and when so constructed the slide block is adapted to fit and slide between the said segmental guides.

In a two strolie internal combustion engine, when constructed as aforesaid, the pump piston is utilized to supply the charge of air or explosive mixture to the power piston, while in a four stroke engine the pump piston may be employed for compressing air or propelling gas or other fluid for use for any desired purpose. Therefore, where as aforesaid the pump piston supplies the charge to the power piston, the larger diameter of the ump piston ensures a higher volumetric e rciency than is obtained in the usual type of engine with crank case compression.

The invention will be more'particularly described with reference to the accompanying drawings. In these drawings theinvention is shown, as an example of construction adapted to a two-stroke internal combustion engine.

Fig. 1 is an elevation partly in section of a portion of a two-stroke engine constructed with three cylinders. Fig. 2 is a vertical section through one of the cylinders taken on the line XY of Fig. 1. Fig. 3 is an elevation taken at right angles to Fig. 2 of the lower or pump end of the double piston. Fig. 4 is a diagram in horizontal section showing the position of the cylinders and passages between them, and Fig. 5 is a vertical section on the line X Y of Fig. 1.

The casing 1 is formed with three cylindrical chambers, the upper portion of each chamber forming a power cylinder 2 and the lower portion of each chamber forming a pump cylinder 8, coaxial with the power cylinder; within these coaxial cylinders is a double piston. This double piston is of sleeve-like construction, forming at its upper end a power piston 4, and at its lower end a pum piston 5, the lower or pump piston 5 being of larger diameter than the upper or power piston 4, and within this lower part is a transverse crosshead 6 formed with guideways for a slide block 7 which provides a bearing for the crank 8. In the walls of the lower part-5 of the piston are slots 9 to allow the pistons to rise and fall within the cylinders, and openings 10 in a plane at right angles to the openings 9 to allow the transverse movement of the slide block 7 in the crosshead guideways 6.

The. transverse bearing surfaces formed by the cross'head 6 are providedwith fixed liners 11 of hardened steel, cast iron or the like, which can in the event of wear be replaced at a very small outlay. They are preferably secured in the crosshead by means of longitudinal ribs 12 on the opposite side to the bearing surfaces, such ribs 12 being secured in recessesor between holding faces in the crosshead by means of cross pins or other locking means.

The slide block 7' 's made with concentric segmental bearing faces for sliding in the transverse guideways 6. It is very advantageous to construct the guideways and sllde block segmentally and concentric on their contact faces, for the bearing then becomes self-aligning, thus reducing wear, and the bearing faces can thus be accurately bored and turned. The slide block may be sufficiently long and the crank given sufficient throw to cause the ends of the slide block to over-run the guides at each end of the sl de block reciprocation, and this over-running has the effect of equalizing the wear on the slide block bearing faces, and further of maintaining efficient lubrication between the slide block and the guide. Each tlme the slide block partly projects outside the gulde there is a tendency ofthe block to tilt out of parallel with the guide owing to thB'IQSIStance being removed from one end of the bearing surface, and on each inward movement of the block the intensity of pressure is least on its leading, i. e. inner, edge with the result that a wedge-shape film of oil is automatically driven between the rubbing surfaces.

The casing 1 is formed as before stated with three cylindrical chambers arranged vertically side by side and leaving vertical passages 13 between them, the lower end of each pump cylinder 3 connects with the vertical passages 13, through a passage let (see Figs. 2 and 5) in which is a rotary valve 15 driven as indicated by chain 15 or by gearing from the crank shaft see Fig. 1), which valve 15 is so constructe as to open alternately to the fuel intake 16 and to the vertical passages 13. These vertical passages 13 are open at their upper ends to a horizontal passage 17 which connects with the upper ends of all the power cylinders 2 for the supply of the combustible mixture, the opening to each cylinder being through a spring-controlled valve 18. The invention is not limited to the precise position-or type of admission valve, the "alve shown at Figs. 1 and 2 being by way of example.

An oil-box 19 (Fig. 1) placed at a suitable height may be employed to deliver oil through regulated sight feeds and tubes 20 to the main bearings of the crank shaft, see Fig. 5. The oil-box 19 may have a sealed cover and the box may be putunder the pressure in the pumps, transfer or receiver passages, by connecting the oil-box up with any of these by a pressure pipe for instance 21 (see Fig. 5) so that the supply'of 'oil to the bearings shall be automatically varied with the load on which the engine runs.

The webs of the crank shaft 8 may be drilled to carry oil to the crank pin (see Fig. 1), and the slide block 7 may be drilled to carry oil to its bearing surfaces. The large diameterof the double piston may be drilled as at 5 for example, so that its guide, i. e. the upper part of the pump cylinder, 1s profusely lubricated by splash from the supply of oil maintained within the double plston by the oil which is thrown out of the revolving crank pin bearing. The power cylinder walls are, however, out olf from this splash lubrication, except via a number of small holes 22 drilled in the power piston skirt for the passage of a certain amount of 'oil mist sufficient for the lubrication of the piston rings. Owing to the fact that the power piston 4 does not bear on the cylinder walls but only the packing rings, the actual amount of oil required on the cylinder walls can be restricted very greatly with the consequence that oil consumption, the evils of carbonization and the risk of oiling up of the sparking plug, are all enormously reduced.

When a rotary valve is used to control the intake and delivery ports of the pump or pumps as shown in the drawings, the oil which works past the pump piston ringnlay be blown through this valve, thus ensuring its lubrication, and the surplus oil then collected at the foot of the transfer passage or receiver space at the gutter 23, (see Fig. 5) and returned by way of, the pipe 21'lcading from the receiver space to the upper portion of the oil-box 19.

lVhen there is no rotary valve to lubricate, the oil which works past the pump piston ring may be trapped at a gutter at the foot of the pump cylinder.

The oil-box may be suitably provided with a filter or chamber 19* for trapping impurities or foregin matter.

lVhen the engine is running, the upstroke of the piston in each of the cylindrical chambers draws explosive mixture into the lower part of the pump cylinder 3 through the intake 16,- valve 15 and passage 14, and the downstroke of the piston compresses --.the mixture in the pump cylinder 3 and forces it along the passage 14 through the valve 15, which at this time has closed the intake passage and opened connection with one of the vertical passages 13. By this means the passages 13 and 17 are. kept charged with compressedexplosive mixture, which upon the downstroke of the piston is admitted through the automatic spring valves 18 to the upper part of the power cylinder. The descent of the power piston 4 opens the exdiametrically op haust 24 in the manner usual in two-stroke engines, and the u stroke of the ower piston 4-gives a fina compression efore exploding the charge.

By the above described means it will be understood that the passages 13 and 17 are always filled with a supply of explosive mixtureunder pressure.

2, Fig. 2, shows a screwthreaded bore enterin the combustion chamber of the power cylin er to receive an ordinary ignition plug.

What I claim as my invention and desire to secure by Letters Patent is a 1. In internal combustionengines of the type specified; the combination with a one piece structure comprising a coaxial power cylinder and larger diameter pump cylinder, and a cylindrical one piece coaxial power and pump piston fittin therein and aving its opposite ends close of a crank shaft, diametrically opposite bearings in the side wall of said pump cylinder to carry said crank shaft, said pump piston having diametrically opposite slots in its wall extending in the direction of the axis of said power and pump pistons to rmit of the passage of said crank shaft an of the reciprocations of said istons, said crank shaft having a crankwit u said cylindrical pump piston, two cross heads at a distance apart formed with and extending across the interior of said pump piston transversely of the axis of sai crank shaft, opposed guiding surfaces on the inner faces of said cross heads, a slide block located between said cross heads and adapted to slide between sa d guides carried thereby, and bearings in said slide block to-receive the crank pm of said crank-shaft.

2. In internal combustion engines of the type specified; the combination with a onepiece structure comprising a coaxial ower cylinder and larger diameter pump cy inder and a cylindrical one piece coaxial power and pump piston fitting therein and having its opposite ends close of a crank shaft, diametrically opposite bearings in the side wall of said pum cylinder to carry said' crank shaft, sai pump piston having ite slots in its wall extending 1n the direction of the axis of said power and pump pistons to permit of the .passage of said crank shaft and of the re- 7 ciprocations of said pistons, said crank shaft having a crank withm said cylindrical pump piston, two cross heads at a distance apart formed with and extending across the intenor of said umpnlpiston transversely of the axis of sai cra shaft, opposed guidmg surfaces on the inner faces of said cross heads, a slide block located between said cross heads and adapted to slide between said guides carried thereby, bearings in said slide block to receive the crank pin of saidcrank shaft, said pump piston having diametrically opposite openings in its wall-at the ends of said cross heads to permit of 4 slide block passing into said enlargements during the operation of the engine.

3. In internal combustion engines of the type specified; the combination with a one piece structure comprising a coaxial ower cylinder and larger diameter pump cy der I and a cylindrical onepie'ce coaxlal power and pump piston fitting therein and having its opposite ends closed; of a crank shaft, diametrically opposite bearings in the side wall of said pump cylinder to carry-said crank shaft, said pump piston having diametrically opposite slots in its wall extending in the direction of the axisof said power and pump pistons to ermit of the passage of said crank shaft an of the reciprocations of said pistons, said crank shaft having a crank entirely within said pump piston, two cross heads at a distance apart formed with and extending across the interior of said pum piston transversely of the axis of said cra shaft, an opposed guide on the inner face of each cross head, said guides having their opposed bearing surfaces segmental and concentric with each other, a slide block adapted to fit and slide between said segmental guides, and hearings in said slide block to receive the crank pm of said crank shaft, said pump piston havin diametrically opposite o enings in its wa l atthe ends of said cross cads to permit of the passage of said slide block in its transverse motions, and said pump cylinder having diametrically op osite mternal enlargements to ermit the en ortions of said slide bloc to pass theremto during the operation of the engine.

4. In an internal combustion en ine, a cylinder, a hollow cylindrical piston aving spaced piston heads, a shaft extending transversely of the cylinder having a crank disposed within the cylindrical walls of the piston and between the spaced heads thereof andcmeans o eratively connecting said piston with sai crank.

h I1:1 witness whereof I have hereunto set my RALPH ALGERNON YEARSLEY. 

